If your app is free, you can write a comment yourself that will appear above it, i've seen this a few times.

You could make it obvious in your description that your taking steps to remedy what the comment said.

Comment: Doesnt work HTC Hero!!!!

Your Description: TODO: Working on HTC Hero Compatability

If your app is paid you can check your google checkout account to see if you can find the matching payment and email them, (although not everyone allows this kind of email communication, ((google privacy setting)))